United States: Patenting Antibodies: Written Description Considerations In Antibody Patents

Written description under 35 U.S.C. §112 is a primary battleground for antibody patent disputes. Small molecule compounds with a small change in structure may possess very different properties, while antibodies with varying amino acid sequences may possess similar binding properties. Claims to a genus of amino acid sequences may not fully cover the essence of the invention, but claims to their functional properties may. So, patent applicants often employ functional claims to cover antibody inventions. This article will discuss several cases relating to antibody claims, in particular, functional antibody claims.

The "Newly Characterized Antigen" Test

"[T]he written description requirement with respect to particularly claimed subject matter is met if the specification shows that the stated inventor has in fact invented what is claimed, that he had possession of it." AbbVie Deutschland GmbH & Co., KG v. Janssen Biotech, Inc., 759 F.3d 1285, 1299 (Fed. Cir. 2014); see also Manual of Patent Examining Procedure (MPEP) §2163 (I) ¶ 2 (9th ed., rev. 08.2017). The specification must fully set forth the claimed invention through words, structures, figures, diagrams, or formulas. MPEP §2163 (I) ¶ 3.   The USPTO, however, previously provided an exception to this general rule for antibody claims with the so-called "newly characterized antigen" test. MPEP §2163 (II)(A)(3)(a) appearing in the "Guidelines for Examination of Patent Applications Under the 35 U.S.C. 112, ¶ 1, 'Written Description' Requirement," 66 Fed. Reg. 1099 (Jan. 5, 2001) and later in the March 2008 USPTO Written Description Training Materials Revision 1. This test allowed written description support for a claim to a genus of antibodies through the disclosure of a newly characterized antigen if the production of such antibodies was conventional or routine. This test was a powerful tool allowing patent owners to obtain claims covering any potential competing products that bind to the same epitope or antigen.

The "newly characterized antigen" test was recently eviscerated by the Federal Circuit inAmgen, Inc. v. Sanofi, 872 F.3d 1367 (Fed. Cir. 2017). In Amgen, a representative claim of the asserted patents reads:

Claim 1. An isolated monoclonal antibody, wherein, when bound to PCSK9, the monoclonal antibody binds to at least one of the following residues: S153, I154, P155, R194, D238, A239, I369, S372, D374, C375, T377, C378, F379, V380, or S381 of SEQ ID NO:3, and wherein the monoclonal antibody blocks binding of PCSK9 to LDL[-]R.

Sanofi contended that the asserted claims did not meet the written description requirement.  At trial in the lower court, an instruction to jury regarding the written description stated:

In the case of a claim to antibodies, the correlation between structure and function may also be satisfied by the disclosure of a newly characterized antigen by its structure, formula, chemical name, or physical properties if you find that the level of skill and knowledge in the art of antibodies at the time of filing was such that production of antibodies against such an antigen was conventional or routine.

Id. at 1376. According to Amgen, that jury instruction was correct because it merely restated the law as set forth in previous Federal Circuit cases. Sanofi argued that disclosure of an antigen could not satisfy the written description requirement for a claim to an antibody. Id.

The Federal Circuit disagreed with Amgen, holding that the jury instruction was improper because it permitted "a finding of adequate written description merely from a finding of ability to make and use[.]" Id. at 1378. The Federal Circuit disparaged the "newly characterized antigen" test as not based on "generally known" or "accurately and readily" ascertainable scientific principles, and "flout[ing] basic legal principles of the written description requirement." Id. "[T]his test allows patentees to claim antibodies by describing something that is not the invention, i.e., the antigen." Id. The Federal Circuit remanded the case for a new trial with a direction to amend the jury instructions.

  After the Amgen v. Sanofi decision, the PTO issued a memorandum on Feb. 22, 2018, with the subject line: "Clarification of Written Description Guidance For Claims Drawn to Antibodies and Status of 2008 Training Materials" to patent examiners to conform to patent examination with the Federal Circuit case law. The memo acknowledged the court's decision on the "newly characterized antigen test":

The Amgen court expressly stated that the so-called "newly characterized antigen" test, which had been based on an example in USPTO-issued training materials and was noted in dicta in several earlier Federal Circuit decisions, should not be used in determining whether there is adequate written description under 35 U.S.C. §112(a) for a claim drawn to an antibody.

Therefore, the memorandum instructs examiners that adequate written description of a newly characterized antigen alone should not be considered an adequate written description of a claimed antibody to that newly characterized antigen, even when the preparation of such an antibody is routine and conventional. According to the USPTO, "personnel should continue to follow the guidance in the MPEP regarding written description (see, e.g., MPEP 2161.01 and 2163), except insofar as MPEP 2163 indicates that disclosure of a fully characterized antigen may provide written descriptive support of an antibody to that antigen."

Possession of Invention

As with other subject matter, in order to meet the written description requirement, a patent application claiming antibodies must disclose the invention in such detail that a person of ordinary skill in the art would understand that the inventors had possession of the claimed invention at the time of filing the patent application. See Ariad Pharms., Inc. v. Eli Lilly and Co., 598 F.3d 1336 (Fed. Cir. 2010). One approach to show possession of an antibody genus involves drafting patents that disclose either a representative number of species or common structural features of antibodies.  See Id. at 1350 (stating "functional claim language can meet the written description requirement when the art has established a correlation between structure and function." emphasis added). But, when the claims are challenged, the courts will look closely to the species disclosed in the specification, as well as the relationship between the disclosed structures and the claimed functionality, if any. There is no hard and fast rule for how much data is sufficient to support an antibody genus claim. But if an accused infringer can identify an antibody that is covered by the patent claims but has significantly different properties from the disclosed species, or if the disclosed species is found not representative of the claimed antibody genus, the patent will likely be declared invalid for lack of written description.

Such was the case in Centocor Ortho Biotech, Inc. v. Abbott Laboratories, 636 F.3d 1341 (Fed. Cir. 2011). There, Centocor sued Abbot for infringement of U.S. Patent No. 7,070,775, claiming a humanized antibody with the ability to bind to a specific epitope:

  1. An isolated recombinant anti-TNF-? anti-body or antigen-binding fragment thereof, said antibody or antigen-binding fragment comprising a human constant region, wherein said antibody or antigen binding fragment (i) competitively inhibits binding of A2 (ATCC Accession No. PTA–7045) to human TNF-?, and (ii) binds to a neutralizing epitope of human TNF-? in vivo with an affinity of at least 1×10 8 liter/mole, measured as an association constant (Ka), as determined by Scatchard analysis.
  2. The antibody or antigen-binding fragment of claim1, wherein the antibody or antigen binding fragment comprises a human constant region and a human variable region.

The Federal Circuit conducted an objective inquiry into the "4 corners of the specification," noting that a "mere wish or plan" for an invention was not enough to satisfy written description. Id. at 1348. The specification must describe an invention understandable to a person of ordinary skill that shows the inventor actually invented it. Id. Abbott argued that Centocor was not in possession of the claimed antibody at the time of application because the specification did not disclose "any fully-human, high affinity, neutralizing, A2 specific antibody," and therefore did not satisfy written description. Id. In Centocor, the Federal Circuit did not reject the "newly characterized antigen test;" rather, the court distinguished the case from the scenarios described in the USPTO guidelines concerning the "newly characterized antigen test."

Abbott showed that Centocor's specification described a single mouse variable region, but that could not serve as written description support for a human variable region, which was "'very different' from the sequence of a human variable region[.]" Id. at 1350. The Federal Circuit agreed with Abbott:

while the patent broadly claims a class of antibodies that contain human variable regions, the specification does not describe a single antibody that satisfies the claim limitations. ... There is nothing in the specification that conveys to one of skill in the art that Centocor possessed fully-human antibodies or human variable regions that fall within the boundaries of the asserted claims.

Id. at 1350-51.

Like functional composition claims, patents must also take care to provide written description support for any claimed antibody genus recited in the method of treatment claims. As the variation in the genus grows, each particular species becomes less representative. One example of this principle, In re Alonso, 545 F.3d 1015 (Fed. Cir. 2008), involved patent claims to a method of treating neurofibrosarcoma reciting a broad antibody genus. The specification at issue disclosed a single antibody, but the patent claimed a method of treatment reciting a large genus of antibodies, essentially any monoclonal antibody that binds to a neurofibrosarcoma:

[a] method of treating neurofibrosarcoma in a human by administering an effective amount of a monoclonal antibody idiotypic to the neurofibrosarcoma of said human, wherein said monoclonal antibody is secreted from a human-human hybridoma derived from the neurofibrosarcoma cells.

The court held that the specification lacked written description for the broad, heterogeneous genus of all monoclonal antibodies against patient-derived neurofibrosarcomas. Even though the applicant had reduced the invention to practice, i.e., they had synthesized at least one representative species and used it in treatment, the Federal Circuit held the specification lacked an adequate description of the antibodies and did not satisfy written description requirements, because just "one compound disclosed by Alonso cannot be said to be representative of a densely populated genus." Id. at 1021.


The Amgen v. Sanofi decision put most functional antibody claims into question, including epitope and competitive binding claims, as well as antibody claims based on a newly characterized antigen. After Amgen v. Sanofi, non-sequence based antibody claims may become more difficult to obtain before the USPTO from a written description standpoint.  Yet, to fully protect the essence of the invention and avoid design-arounds, such claims are extremely valuable to patent owners. To obtain antibody genus claims beyond those defined by sequences, the patent applicant will need to make and test a sufficient number of representative antibodies across the claimed genus, or establish a clear structure/function relationship among the members of the genus.  Patent applicants should carefully assess the amount of data they have acquired, in comparison to the scope of claims that they wish to obtain, before rushing to the Patent Office.

Previously published in IPWatchdog.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.

To print this article, all you need is to be registered on Mondaq.com.

Click to Login as an existing user or Register so you can print this article.

Events from this Firm
18 Dec 2018, Webinar, Washington, DC, United States

As part of Strafford Publications’ webinar series, Finnegan attorneys Adriana Burgy, Chris Johns, and Show Summary

2 Jan 2019, Conference, Washington, DC, United States

Finnegan is a Silver sponsor of the 36th annual National CLE Conference. Finnegan partner Erika Arner will co-present “The Interplay Between IPRs and Other PTAB Trial Proceedings and Litigation—Strategy and Lessons.

6 Jan 2019, Webinar, Washington, DC, United States

As part of Strafford Publications’ webinar series, Finnegan attorneys Virginia Carron and Jessica Marks will consider patent eligibility issues with engineered natural products.

Similar Articles
Relevancy Powered by MondaqAI
In association with
Related Topics
Similar Articles
Relevancy Powered by MondaqAI
Related Articles
Related Video
Up-coming Events Search
Font Size:
Mondaq on Twitter
Register for Access and our Free Biweekly Alert for
This service is completely free. Access 250,000 archived articles from 100+ countries and get a personalised email twice a week covering developments (and yes, our lawyers like to think you’ve read our Disclaimer).
Email Address
Company Name
Confirm Password
Mondaq Topics -- Select your Interests
 Law Performance
 Law Practice
 Media & IT
 Real Estate
 Wealth Mgt
Asia Pacific
European Union
Latin America
Middle East
United States
Worldwide Updates
Registration (you must scroll down to set your data preferences)

Mondaq Ltd requires you to register and provide information that personally identifies you, including your content preferences, for three primary purposes (full details of Mondaq’s use of your personal data can be found in our Privacy and Cookies Notice):

  • To allow you to personalize the Mondaq websites you are visiting to show content ("Content") relevant to your interests.
  • To enable features such as password reminder, news alerts, email a colleague, and linking from Mondaq (and its affiliate sites) to your website.
  • To produce demographic feedback for our content providers ("Contributors") who contribute Content for free for your use.

Mondaq hopes that our registered users will support us in maintaining our free to view business model by consenting to our use of your personal data as described below.

Mondaq has a "free to view" business model. Our services are paid for by Contributors in exchange for Mondaq providing them with access to information about who accesses their content. Once personal data is transferred to our Contributors they become a data controller of this personal data. They use it to measure the response that their articles are receiving, as a form of market research. They may also use it to provide Mondaq users with information about their products and services.

Details of each Contributor to which your personal data will be transferred is clearly stated within the Content that you access. For full details of how this Contributor will use your personal data, you should review the Contributor’s own Privacy Notice.

Please indicate your preference below:

Yes, I am happy to support Mondaq in maintaining its free to view business model by agreeing to allow Mondaq to share my personal data with Contributors whose Content I access
No, I do not want Mondaq to share my personal data with Contributors

Also please let us know whether you are happy to receive communications promoting products and services offered by Mondaq:

Yes, I am happy to received promotional communications from Mondaq
No, please do not send me promotional communications from Mondaq
Terms & Conditions

Mondaq.com (the Website) is owned and managed by Mondaq Ltd (Mondaq). Mondaq grants you a non-exclusive, revocable licence to access the Website and associated services, such as the Mondaq News Alerts (Services), subject to and in consideration of your compliance with the following terms and conditions of use (Terms). Your use of the Website and/or Services constitutes your agreement to the Terms. Mondaq may terminate your use of the Website and Services if you are in breach of these Terms or if Mondaq decides to terminate the licence granted hereunder for any reason whatsoever.

Use of www.mondaq.com

To Use Mondaq.com you must be: eighteen (18) years old or over; legally capable of entering into binding contracts; and not in any way prohibited by the applicable law to enter into these Terms in the jurisdiction which you are currently located.

You may use the Website as an unregistered user, however, you are required to register as a user if you wish to read the full text of the Content or to receive the Services.

You may not modify, publish, transmit, transfer or sell, reproduce, create derivative works from, distribute, perform, link, display, or in any way exploit any of the Content, in whole or in part, except as expressly permitted in these Terms or with the prior written consent of Mondaq. You may not use electronic or other means to extract details or information from the Content. Nor shall you extract information about users or Contributors in order to offer them any services or products.

In your use of the Website and/or Services you shall: comply with all applicable laws, regulations, directives and legislations which apply to your Use of the Website and/or Services in whatever country you are physically located including without limitation any and all consumer law, export control laws and regulations; provide to us true, correct and accurate information and promptly inform us in the event that any information that you have provided to us changes or becomes inaccurate; notify Mondaq immediately of any circumstances where you have reason to believe that any Intellectual Property Rights or any other rights of any third party may have been infringed; co-operate with reasonable security or other checks or requests for information made by Mondaq from time to time; and at all times be fully liable for the breach of any of these Terms by a third party using your login details to access the Website and/or Services

however, you shall not: do anything likely to impair, interfere with or damage or cause harm or distress to any persons, or the network; do anything that will infringe any Intellectual Property Rights or other rights of Mondaq or any third party; or use the Website, Services and/or Content otherwise than in accordance with these Terms; use any trade marks or service marks of Mondaq or the Contributors, or do anything which may be seen to take unfair advantage of the reputation and goodwill of Mondaq or the Contributors, or the Website, Services and/or Content.

Mondaq reserves the right, in its sole discretion, to take any action that it deems necessary and appropriate in the event it considers that there is a breach or threatened breach of the Terms.

Mondaq’s Rights and Obligations

Unless otherwise expressly set out to the contrary, nothing in these Terms shall serve to transfer from Mondaq to you, any Intellectual Property Rights owned by and/or licensed to Mondaq and all rights, title and interest in and to such Intellectual Property Rights will remain exclusively with Mondaq and/or its licensors.

Mondaq shall use its reasonable endeavours to make the Website and Services available to you at all times, but we cannot guarantee an uninterrupted and fault free service.

Mondaq reserves the right to make changes to the services and/or the Website or part thereof, from time to time, and we may add, remove, modify and/or vary any elements of features and functionalities of the Website or the services.

Mondaq also reserves the right from time to time to monitor your Use of the Website and/or services.


The Content is general information only. It is not intended to constitute legal advice or seek to be the complete and comprehensive statement of the law, nor is it intended to address your specific requirements or provide advice on which reliance should be placed. Mondaq and/or its Contributors and other suppliers make no representations about the suitability of the information contained in the Content for any purpose. All Content provided "as is" without warranty of any kind. Mondaq and/or its Contributors and other suppliers hereby exclude and disclaim all representations, warranties or guarantees with regard to the Content, including all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement. To the maximum extent permitted by law, Mondaq expressly excludes all representations, warranties, obligations, and liabilities arising out of or in connection with all Content. In no event shall Mondaq and/or its respective suppliers be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use of the Content or performance of Mondaq’s Services.


Mondaq may alter or amend these Terms by amending them on the Website. By continuing to Use the Services and/or the Website after such amendment, you will be deemed to have accepted any amendment to these Terms.

These Terms shall be governed by and construed in accordance with the laws of England and Wales and you irrevocably submit to the exclusive jurisdiction of the courts of England and Wales to settle any dispute which may arise out of or in connection with these Terms. If you live outside the United Kingdom, English law shall apply only to the extent that English law shall not deprive you of any legal protection accorded in accordance with the law of the place where you are habitually resident ("Local Law"). In the event English law deprives you of any legal protection which is accorded to you under Local Law, then these terms shall be governed by Local Law and any dispute or claim arising out of or in connection with these Terms shall be subject to the non-exclusive jurisdiction of the courts where you are habitually resident.

You may print and keep a copy of these Terms, which form the entire agreement between you and Mondaq and supersede any other communications or advertising in respect of the Service and/or the Website.

No delay in exercising or non-exercise by you and/or Mondaq of any of its rights under or in connection with these Terms shall operate as a waiver or release of each of your or Mondaq’s right. Rather, any such waiver or release must be specifically granted in writing signed by the party granting it.

If any part of these Terms is held unenforceable, that part shall be enforced to the maximum extent permissible so as to give effect to the intent of the parties, and the Terms shall continue in full force and effect.

Mondaq shall not incur any liability to you on account of any loss or damage resulting from any delay or failure to perform all or any part of these Terms if such delay or failure is caused, in whole or in part, by events, occurrences, or causes beyond the control of Mondaq. Such events, occurrences or causes will include, without limitation, acts of God, strikes, lockouts, server and network failure, riots, acts of war, earthquakes, fire and explosions.

By clicking Register you state you have read and agree to our Terms and Conditions